Reddit reviews John Constantine, Hellblazer Vol. 6: Bloodlines

Hellblazer is a pretty linear series. Pick up issue one and go from there. There are a few annuals and extra stories and whatnot, but Vertigo has been releasing awesome trades of every Hellblazer story in chronological order. Just buy these, and continue to buy this series until it is all collected.

• Vol 01: Original Sins
  
• Vol 02: The Devil You Know
  
• Vol 03: The Fear Machine
  
• Vol 04: The Family Man
  
• Vol 05: Dangerous Habits
  
• Vol 06: Bloodlines
  
• Vol 07: Tainted Love
  
• Vol 08: Rake at the Gates of Hell - Preorder
  
• Vol 09: Critical Mass - Preorder
  
  If you get all of these trades, you will have:
  
  
• Issues #001-096 of Hellblazer
  
• Swamp Thing #76-77 (Vol 01)
  
• Hellblazer Annual #01 (Vol 02)
  
• The Horrorist #01-02 (Vol 02)
  
• Vertigo Secret Files: Hellblazer #01 (Vol 04)
  
• Hellblazer Special #01 (Vol 07)
  
• Vertigo Jam #01 (Vol 07)
  
• Heartland One-Shot (Vol 08)
  
  And that's only in volumes 01-09. Vertigo has been doing a great job with this series, and I truly believe that they will collect all of it.

I'd read The Saga of the Swamp, mostly just because it is amazing, first, and it is his original introduction. But if you just wanna jump right into John's stories I would say the best techniques is to jump on to the run of the writer you like best. If you are familiar with comics, especially vertigo comics, at all you will be familiar with many of the creators including Jamie Delano, Warren Ellis, Garth Ennis, Mike Carey, Brian Azzerello, and Pete Milligan among many others. There are also short runs from other famous writers such as; Grant Morrison, Neil Gaiman, Jason Aaron, and more, that are worth checking out.

If everything else I said is meaningless to you. I would most readily recommend Mike Carey and Garth Ennis' runs.
Here are the Ennis Trades (6 or 7 are my favorite, but they must be read in order:
http://www.amazon.com/John-Constantine-Hellblazer-Dangerous-Edition/dp/1401238025/ref=sr_1_6?ie=UTF8&qid=1414271898&sr=8-6&keywords=hellblazer

http://www.amazon.com/John-Constantine-Hellblazer-Vol-Bloodlines/dp/1401240437/ref=sr_1_8?ie=UTF8&qid=1414271898&sr=8-8&keywords=hellblazer

http://www.amazon.com/John-Constantine-Hellblazer-Vol-Tainted/dp/1401243037/ref=sr_1_7?ie=UTF8&qid=1414271898&sr=8-7&keywords=hellblazer

http://www.amazon.com/John-Constantine-Hellblazer-Vol-Graphic/dp/1401247490/ref=sr_1_9?ie=UTF8&qid=1414271898&sr=8-9&keywords=hellblazer

Here are the Carey Ones (they can be read in any order All His Engines is particularly a stand alone graphic novel - My favorite is The Red Sepulchre):

http://www.amazon.com/John-Constantine-Hellblazer-Red-Sepulchre/dp/1401204856/ref=sr_1_4?ie=UTF8&qid=1414272092&sr=8-4&keywords=hellblazer+carey

http://www.amazon.com/John-Constantine-Hellblazer-Stations-Cross/dp/1401210023/ref=sr_1_3?ie=UTF8&qid=1414272092&sr=8-3&keywords=hellblazer+carey

http://www.amazon.com/John-Constantine-Hellblazer-Reasons-Cheerful/dp/1401212514/ref=sr_1_1?ie=UTF8&qid=1414272092&sr=8-1&keywords=hellblazer+carey

http://www.amazon.com/John-Constantine-Hellblazer-All-Engines/dp/1401203175/ref=sr_1_6?ie=UTF8&qid=1414272092&sr=8-6&keywords=hellblazer+carey